CVE-2016-1938: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 3.2% chance of exploitation in the next 30 days.

The s_mp_div function in lib/freebl/mpi/mpi.c in Mozilla Network Security Services (NSS) before 3.21, as used in Mozilla Firefox before 44.0, improperly divides numbers, which might make it easier for remote attackers to defeat cryptographic protection mechanisms by leveraging use of the (1) mp_div or (2) mp_exptmod function.

Affected products

• Mozilla Firefox: up to and including 43.0.4
• Mozilla Nss: up to and including 3.20.1
• Opensuse Leap: version 42.1 only
• Opensuse Opensuse: version 13.1 only; version 13.2 only

Published 2016-01-31. Last modified 2026-06-17.